Coral oxygen isotope and in situ records capture the 2015/2016 El Niño event in the central equatorial Pacific

Central Equatorial Pacific Warming and Freshening in the Twentieth Century: Insights From a Coral Ensemble Approach

“…It is worth noting that the contribution of SST and SSS to the twentieth century Kiritimati coral δ 18 O trend is markedly different than the ∼70% SST and ∼30% δ 18 O sw contributions to coral δ 18 O anomalies documented across recent strong El Niño events at the site (O'Connor et al, 2021). Frequency-dependent relationships between SST and SSS have been inferred from other studies (Liu and Di Lorenzo, 2018;Xie et al, 2010), including coral studies (Russon et al, 2013), and our study further supports the notion that different physical processes likely dominate regional climate across interannual, multi-decadal and centennial timescales…”

“…We present three twentieth century Kiritimati coral δ 18 O composites: (a) fossil coral δ 18 O composite records spanning 1952-1972 and 1978-2006 constructed by splicing together new and existing fossil coral δ 18 O data; (b) a modern coral δ 18 O composite constructed from previously published records (Evans et al, 1999;Cobb et al, 2013;Grothe et al, 2019;Nurhati et al, 2011;O'Connor et al, 2021); and (3) a composite of all modern and fossil coral records spanning 1891-2016 (Figures 1 and 2a). Coral δ 18 O composites were constructed from centered δ 18 O records, where mean offsets in coral δ 18 O were removed by subtracting the mean δ 18 O value of each record from the mean δ 18 O value of all overlapping records (Sayani et al, 2019).…”

“…Figure 1. (a) Twentieth century Kiritimati modern (gray;Cobb et al, 2013;Grothe et al, 2019;Nurhati et al, 2009;O'Connor et al, 2021) and fossil coral (various colors) δ 18 O sequences. U/Th dates (triangles) for the fossil coral sequences are shown with 2σ error bars in corresponding colors (TableS2in Supporting Information S1).…”

“…Figure 2. (a) Composite Kiritimati coral δ 18 O record, built using published modern(Cobb et al, 2013;Grothe et al, 2019;Nurhati et al, 2009;O'Connor et al, 2021) and new fossil coral δ 18 O sequences, with corresponding ±2σ uncertainties (light blue shading). Uncertainties are not visible on the scale shown from 1938 to 2016 CE.…”

Diverse Orbital‐Scale Variations of Precipitation Oxygen Isotopes in the Northern Hemisphere Mid‐Latitudes: A Comparative Study Between East Asia and North America

“…The δ 18 O p or δ 18 O variations during geological periods are documented in various paleoclimate archives and are therefore often served as effective tools for exploring paleoclimate conditions. For instance, coral δ 18 O records in tropical oceans are recognized as indicators of ocean temperature fluctuations (O'Connor et al, 2021); stalagmite δ 18 O data from the Asian monsoon regions are generally considered to reflect changes in rainfall (Sinha et al, 2005) or monsoon intensity (Kathayat et al, 2016;Wang et al, 2008); tree-ring δ 18 O in the middle-to high-latitudes have become an important way of documenting temperature variation (Bégin et al, 2015;Gray & Thompson, 1976); and δ 18 O in ice core records collected from polar and highland regions preserve local temperature histories (Alley, 2000;Tian et al, 2006). Despite these different types of geological archives spread across the world, there are only a few δ 18 O series from cave deposits available for exploring long-term climatic changes during the late Quaternary in the Northern Hemisphere (NH) mid-latitude continents, such as the Ton Cave in Central Asia and Buckeye Creek Cave in North America (Cheng et al, 2019).…”